Generic access network gan bridges the lte and umts networks. Handover between different radio technology networks, for example gsm umts and umts well look at intra lte handovers with x2ap signaling and s1ap signaling first, then interrat handovers in lte i. The schemes evaluated were voice call continuity vcc for umts to lte handover. This container is used for inter 3gpp rat handovers from saelte to utran. Circuit switched call setup with ims anchoring if the vcc terminal moves from umts to lte coverage, handover to lte will occur using. This page on umts vs lte describes difference between umts and lte systems. Ue decides to move back to lte network and sends a connection request to lte. We formally model four handover procedures between lteumts and ltelte nodes. Developed and maintained by the 3gpp 3rd generation partnership project, umts is a component of the international telecommunications union imt2000 standard set and compares with the cdma2000 standard set for networks based on the competing cdmaone. Handover procedure in lte network gls maps designed for x2 application protocol x2ap is used to coordinate handovers and perform load management between enodeb evolved node b network elements source enodeb and target enodeb. While the lte handover procedures defined in release 8 provide mobility support, they may not be suitable for all scenarios and could result in unsatisfactory user experience even when compared to legacy 2g and 3g systems. Handover aims to provide continuity of mobile services to a user traveling over cell boundaries in a cellular infrastructure.
Handover in lte lte telecommunication transmission. Lte cells, and use the faster intra rat handover procedure. Lte architecture supports hard qos, with endtoend quality of service and guaranteed bit rate gbr for radio bearers. Lte x2 handover between enodebs served by the same mme. Handover between different radio technology networks, for example gsmumts and umts well look at intralte handovers with x2ap signaling and s1ap signaling first, then interrat handovers in lte i. A horizontal handover occurs when a mobile node switches from one cell tower to another cell tower, depicted by the dotted enodebs in figure 1. The cross reference between gsm, umts, 3gpp and etsi identities can be.
The simplest multi cell cases would be between two lte cells. Not a full form of umts handover, but the ue communicates with more than one sector managed by the same nodeb. Nov 26, 2012 this tutorial describes lte handover types and procedures. Abstract universal mobile telephone system umts is a third generation. Test measurement challenges and field environment test planning. Most of the previous solutions that are proposed to solve the. Srvcc however stands out as it is deemed to be more longterm than the other schemes. In this case source and target cells are part of the same lte network.
First, the 3gpp cell reselection and handover mechanism are outlined in the first. In umts systems different handover types have been introduced to cope also with other requirements as load control, coverage provisioning and offering quality of services. Nov 06, 2016 when lte system was developed one of the big technical feature from umts softsofter handover was missing from the architecture. Umts handover description free download as powerpoint presentation. Jun 03, 2017 the data path switching goes through several steps to accomplish a seamless handover. Mobility and seamless handoff were requirements from the start, as was a requirement for. Request pdf on jul 1, 2015, piergiuseppe bettassa copet and others published formal verification of lteumts handover procedures find, read and cite all the research you need on researchgate. This tutorial section on femtocell basics covers following sub topics. Intralte intramme sgw handover using the x2 interface. If the ue reports a 2d event, that is, the current carrier is in poor signal quality, the ue reports a 2e event after interfrequency measurement is started that is, the signal quality of the measured interfrequency neighboring cell is also poor, the rnc needs to configure and start interrat measurement 3a or 3c event to the ue, and then. However, other nations and companies do play an active role in the lte project. Formal verification of lteumts handover procedures. It is a handbook of umts lte epc handover call flows. The thesis work is about the investigation of different handovers in the 3g umts network which is the vital issue to the network to maintain the users connection during in the ongoing.
In such networks, the mobile phones fall back to 2g or 3g networks that support circuit switch calls. There are many specific reasons why lte dropped altogether soft. In this video we are going to discuss about lte handover overview interintrainterrat do like it, share and subscribe the channel if you havent yet. Works with gsmedge umts systems utilizing existing 2g and 3g spectrum and new spectrum. An overview article pdf available in wireless personal communications 774 august 2014 with 429 reads how we measure reads. As discussed before, both volga and csfb are considered to be interim solutions. Lte x2 handover in eventtriggered handover procedures, each ue evaluates the event condition every time a new. Umts to from gsm or umts to from 4g lte, etc each of the different types of handover is used on different occasions dependent upon the conditions.
Performance evaluation of handover from umts to lte using. Intra lte intrammesgw handover using the x2 interface this procedure is used to handover a ue from a source enodeb senb to a target enodeb tenb using the x2 interface when the mobility management entity. This document is originally edited by justin ma and it is free to share to everyone who are interested. Handover principles and handover measurements in lte. According to statistics2, the most common english surname is smith, which corresponds to physical layer cell identity group 0. Mobile communications gsm and third generation systems like universal mobile telecommunications system umts are however designed for voice optimized performance, and are relatively expensive to operate.
Lte users should be able to make voice calls from their terminal and have access to basic data services even when they are in areas without lte coverage. There is a centralized controller called radio network controller rnc to perform handover control for each ue in the architecture of wcdma. Handover between lte and 3g radio access technologies. Handover happens toward the other lte nodes intermme and intersgw interrat. Because the lte mac is fully scheduled, qos is a natural fit. Pdf enhanced handover mechanism in long term evolution lte. This chapter focuses on introduction of proposed interrat handover solution for interworking umts with wimax. The tenb checks for resource availability and, if available, reserves the resources and sends back the handover request acknowledge message. Handover procedure there are two types of handover procedure in lte for ues in active mode. Soft handover issues in radio resource management for 3g wcdma networks. Thus applications dont even come to know about this handover. Comprehesive coverage of umts 3g news, licensing, business developments, 3g wcdma telecommunication technology, multi media mobile phones and future communications. The universal mobile telecommunications system umts is a third generation mobile cellular system for networks based on the gsm standard. I have include wcdma and lte on top of current gsm version.
Test measurement challenges and field environment test planning school of electrical engineering master. Handover procedures are a key function of lte enbs. Furthermore, lte sae supports not only intrasystem and inter. Just as ethernet and the internet have different types of qos, for example, various levels of qos can be applied to lte traffic for different applications. Vertical handover solutions over lte advanced wireless networks. If the target cell id is known by enodeb, it will proceed with the handover.
This report investigates the performance of interradio access technology voice handover between lte and umts. The goal of lte was to increase the capacity and speed of wireless data networks. Impact signal propagation parameters to umtslte handover. The rules vary with different types of interrat handover, that is, the 4 factors will decide if the interrat handover is allowed. Jul 04, 2014 user description, gsm umts lte cell reselection and handover 4. Handover process in lte, lte handover tutorial teletopix. This may be made possible by the control layer integration between lte and 5g, which is part of the proposals around tight integration 16. The analysis found vulnerabilities when optional security mechanism are disabled.
Lte x2 handover sequence diagrams lte long term evolution. The research topic of this thesis which is lte handover performance. In the lte to lte handover models both x2 and s1, two authentication queries similar to the first two ones of the lte to umts and umts to lte handovers have been defined. Several functional elements take part during the handover. Lte therefore allows smooth, seamless service handover in areas of hspa, wcdma or gsmgprsedge coverage. Lte long term evolution is a fourth generation cellular network technology that provides improved performance related to data rate, coverage and capacity compared to legacy cellular systems. Fixed wireless and wired standards are already approaching or achieving 100 mbps or faster, and lte is a way. When the reporting threshold condition is fulfilled, the ue sends handover measurement reports to the serving enodeb. Handover in particular is more complicated in lte as lte.
This form of handover is supported within gsm and a neighbour list was established to enable this occur easily. Lte stands for long term evolution and it was started as a project in 2004 by telecommunication body known as the third generation partnership project 3gpp. When a handover takes place from lte to wcdma data call, then after the call is released in wcdma, the ue will lose its ip, as in wcdma, ip is given to a user only in a data call whereas in lte ue has the ip since the time it. Umts handover overview umts intrafrequency handover strategy umts interfrequency handover strategy umts interrat handover policy umts srns relocation. Umts handover description mobile technology physical. The umts world is an 3g mobile system news and information provider. Lte ue can detect intra lte neighbors without neighbor lists which simplifies network management. For umts access stratumas and non access stratumnas, refer read umts protocol stack article. Performance evaluation of voice call handover between umts. We recently had a training on lte and there was a question that was not answered. The senb issues a handover request message to the tenb. The messaging in x2 handover is detailed in lte x2.
Leaving circuit switched technology far behind lte became the first allip mobile network. Request pdf on jul 1, 2015, piergiuseppe bettassa copet and others published formal verification of lte umts handover procedures find, read and cite all the research you need on researchgate. Formal verification of lteumts handover procedures request pdf. Lte to 3g circuit switched fallback lte to3gcircuitswitchedfallback.
Lte long term evolution long term evolution signaling flows and tutorials for lte. Lte technology is a based on a 3gpp standard that provides for a downlink speed of up to 150 megabits per second mbps and an uplink speed of up to 50 mbps. With the deployment of new technologies still on the way, the era beyond 3g and 4g requires that cellular and radio technologies need to work together. Jun 16, 2011 in umts systems different handover types have been introduced to cope also with other requirements as load control, coverage provisioning and offering quality of services. As the gsm 2g network is normally more extensive than the 3g network, this type of handover does not normally occur when the ue leaves a coverage area and must quickly find a new base station to. Jul 09, 2014 it is a handbook of umts lte epc handover call flows. Lte networks and the wideband code division multiple. Handover mechanisms in 3gpp long term evolution lte. Lte x2 handover sequence diagrams detailed message flow analysis of lte x2 handovers eventstudio system designer sequence diagram based systems engineering tool. Now we examine the same flow at a higher level of abstraction. High data rates can be achieved in both downlink as well as uplink. Composed of phy, mac, rlc, pdcp, rrc, read lte protocol stack tutorial. Cell search and cell selection in umts lte application note.
Lte evolved from an earlier 3gpp system known as the universal mobile telecommunication system umts, which in turn evolved from the global system for mobile communications gsm. The physical layer itself maintains the continuous connection model, especially on the downlink, where there is continuous transmission. The x2 handover is used when direct connectivity between source and target enbs exists. However, even the intra rat handover may not be a good solution for a seamless and ultrafast switch between the two air interfaces. Lte stands for long term evolution and is a registered trademark owned by etsi european telecommunications standards institute for the wireless data communications technology and a development of the gsm umts standards. Lte s1 handover s1 handover lte mobile enodeb network core. Like other mobile networks lte also have big challenges when it comes to mobility areas like handover and reselection. Formal verification of lteumts and ltelte handover. Handover in particular is more complicated in lte as lte has. Handover in lte free download as powerpoint presentation. Performance comparison of dual connectivity and hard handover.
Ueassisted measurements are made and reported by the ue to the network. Pdf handover scenario and procedure in ltebased femtocell. More complicated probably the most complicated cases are the multi cell scenario among different technologies different rats. This form of handover occurs when the base station hands off the ue by passing it the details of the new cell to the ue. The research topic of this thesis is handover from lte to 3g cellular networks, which is a. Visualether protocol analyzer wireshark based visual protocol analysis and system design reverse engineering tool. Pdf of the x coordinate of all users in one simulation. Both the systems are used for cellular mobile communications. Pdf umtslteepc call flows for handovers jachang ma. In this context, one of the main goals of lte is to provide fast and seamless handover from one. In comparison, ues are the same, different radios, on one end lte, and into the future a 5g radio.
Jun 03, 2017 lte enodebs can directly communicate with other enodebs on the x2 interface. This paper discusses the lte handover procedures that are standardized in 3gpp release 8 and describes a new lte handover. Lte changed the way traditional mobile network were working. Long term evolution protocol overview nxp semiconductors. This article describes technologies for enabling smooth voice and tv phone interd\ omain handover especially during the radio access network migration phase when lte and 3g networks coexist and where both lte and 3g radiosnetwork domains will. They are intended to reduce interruption time compared to the circuitswitched handover process in 2g networks. The standards define some optional security features, and operator can ignore them. All the possible combinations of security policies have been considered. Evolutionary analysis of gsm, umts and lte mobile network. Main page architecture testing manufacturers femtocell vs wifi types interference timing and sync. Seamless voice handover between packet switched lte and the circuit switched umts network is therefore an important tool in solving this problem.
Lte s1 handover s1 handover lte mobile enodeb network core network ue target enodeb source enodeb mme sgw pgw eventstudio system designer 6 17feb14 21. Gsm and universal mobile telecommunications system umts standards, commonly called 3g. Pdf soft handover issues in radio resource management for. Interdomain handover technologies in lte for voice volte. Voice communication was primary application, with data added recently. Supports handover and roaming to existing mobile networks. The rules for enabling umts togsm handover are based on the parameter service handover indicator and the three types of capability parameters. Lte longterm evolution this section explains what lte is and the components which it consists of, in order to get an understanding of the technology and how horizontal handovers are facilitated. This form of handover occurs when mobiles have to change between radio access technologies, e.
In this context, one of the main goals of lte is to provide fast and seamless handover from one cell to another to meet a strict. Thoroughly evaluating the performance of lte enbs requires testing multiple handover procedures, shown in. User description, gsm umts lte cell reselection and handover 4. The s1 handover procedure is performed between two enbs without the x2 interface. This tutorial describes lte handover types and procedures. The ue receives the rrcconnectionreconfiguration message with necessary parameters i. Handover procedure in lte network gl communications inc. We call this kind case as intrarat multi cell scenario. Late path switch only once the handover is successful, the packet core is involved. Having selected a suitable base station the handover takes place, but without any time synchronisation having occurred. The enodeb sends measurement control messages to the ue giving reporting thresholds. Apr 10, 2010 the handover request acknowledge message includes a transparent container to be sent to the ue as an rrc message to perform the handover. In the future, voice and tv phone services will also be provided in lte by way of handset terminals. It mentions types of femtocell handover as per 2g, 3g, 4g, lte, umts, wimax, gsm standards.
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